Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Mechanical Inspection: Compression
Start engine and warm to normal operating temperature. Turn ignition off. Release fuel pressure. See FUEL PRESSURE RELEASE in FUEL SYSTEM. On Distributorless Ignition System (DIS) equipped models, remove all ignition coils. On all other models, disconnect distributor 2-pin harness connector (for ignition coil). On all models, remove all spark plugs. Depress accelerator pedal fully to hold throttle valve wide open. Attach compression tester to cylinder No. 1. Crank engine at specified speed and record highest gauge indication. See appropriate COMPRESSION SPECIFICATIONS table. Repeat measurement for each cylinder.
| Application | Specification | ||
|---|---|---|---|
| Normal Compression Pressure | |||
| Altima | 182 psi (12.8 kg/cm2 ) | ||
| Frontier & Xterra | 178 psi (12.5 kg/cm2 ) | ||
| Sentra | |||
| 1.8L | 192 psi (13.5 kg/cm2 ) | ||
| 2.5L | 181 psi (12.8 kg/cm2 ) | ||
| Minimum Compression Pressure | |||
| Altima | 154 psi (10.8 kg/cm2 ) | ||
| Frontier & Xterra | 149 psi (10.5 kg/cm2 ) | ||
| Sentra | |||
| 1.8L | 168 psi (11.50 kg/cm2 ) | ||
| 2.5L | 154 psi (10.8 kg/cm2 ) | ||
| Maximum Variation Between Cylinders | 14 psi (1.0 kg/cm2 ) | ||
| Application | Specification | |
|---|---|---|
| Normal Compression Pressure | ||
| Altima, Maxima, Murano, Pathfinder & 350Z | 185 psi (13.0 kg/cm2 ) | |
| Frontier & Xterra | 174 psi (12.2 kg/cm2 ) | |
| Minimum Compression Pressure | ||
| Altima, Maxima, Murano, Pathfinder & 350Z | 142 psi (10.0 kg/cm2 ) | |
| Frontier & Xterra | 128 psi (9.0 kg/cm2 ) | |
| Maximum Variation Between Cylinders | 14 psi (1.0 kg/cm2 ) | |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.